Electric fence control unit



April 18, 1944. s HARRls 2,346,965

ELECTRIC FENCE CONTROL UNIT Filed April 10, 1939 ,Rvewiin Patented Apr. 18, 1944 UNITED STATES PATENT OFFICE ELECTRIC FENCE CONTROL UNIT Thaddeus S. Harris, Waverly, Ill.

Application April-10, 1939, Serial No. 256,999

4 Claims.

My invention relates to that class of electric control units in which; successive. high voltage shocks are produced by providing an oscillator member to alternately make and break the circuit through a combined magnetic and shock coil. This invention particularly relates to automatically controlling the oscillations so that they periodically cease for ashort time, then automatically commence again. The advantages of this method of operation are, first, the shocks occur in groupswith a. controllable period of time separating the groups, so that the amount of battery current required may be reduced very greatly without entirely shutting off the unit as is often done. Second, the strength of the shocks in each group varies widely, from a very weak shock at the first break of the circuit to much stronger ones as the oscillations build up in amplitude, due to the fact that the circuit is closed longer, giving a greater degree of saturation of the coil core. Also the time varies between the several shocks of each group, which is a further protection to the animals, as required in some localities.

Considerable variation can be made in the different essential members of the complete unit without departing from the basic form of the invention, such as using a pendulum instead of a balance wheel as the oscillator member, and a diaphragm chamber instead of a liquid dashpot as the timing or group period control member.

' The accompanying drawing illustrates a front elevation of the invention, with certain parts shown in vertical section.

Base, l, supports the panel, 2, to which is fixed the coil member, 3. Coil 3 has a central core upon which is wound the primary winding with terminals 3', 3", and a secondary winding of finer wire with terminals, 4 4". A flexibly mounted armature lever, 4, is fixed to thebase at its lower end and has a suitable switch contact point, 6', at its free end.

A balance wheel, 5, is pivoted on panel, 2, by shaft, l. An arm, '1 is fixed to the rim of wheel, 5, and has a contact point, t", which engages point, 6'. A coil spring, 6, is disposed to rotate wheel, 5, to cause contact 6" carried by arm, 1 to engage contact 6' carried by lever i; A post 1, is, fixed to wheel, 5, extending at right angles .to the wheelplane.

Acontrol lever, 8, is pivoted on post, 9, to move ina plane parallel to the wheel, 5. A spring, H, and stop 12 determine the normal position of leyer-8. Or, if lever B is-properly balanced, spring l-Lmay be omitted. An interrupter assemblyis fixed to arm 8, to interrupt the return or counterclockwise movement of wheel 5, whenever its clockwise movement caused by actuation of the armature amounts to more than about three fourths of a complete revolution from its normal position, said assembly comprising the arm, 8, the cam block, 8", and the spring tip, l l, which is fixed to block 8". Arm 8* is disposed so that post I may move behind it, but the cam block, 8 and spring tip,v ll extend from arm, 8 toward the wheel, so that post I first engages the outer or right hand surface of the. spring tip l:l,.as seen on the drawing, to deflectit slightly leftward and then slip past it, and then as post i reverses its movement it reengages the spring tip and cam block on the inner side, to retard the return movement of wheel, 5, until lever arm, 8' and lever, 8 have been forced to rotate about their pivot away from the wheel center sufficiently to release post, 1.

A second arm, 10, is also fixed to lever B, and has the cam block, I 0", to which is fixed the spring tip, lil, these being so disposed that the post I engages them as it moves from block, 8 to continueits reverse movement. Spring tip It and block IE1 areso disposed that. the pressure from post 1, causes arm, Hi to become moved away from wheel, 5, eventually allowing post I to move to the tip of the spring. A very short post, 1" is mountedon the tip of spring, If)", and is suitably formed to engage post I, to momentarily. halt the movement of wheel, 5. A spring, H, is disposed to cause lever, B to continue to move after post, .7, has engaged post, 'i, so that finally post, I, is released from post, 1'', with a snap action which causes the spring tip. to move back clear of the next throw of wheel, 5, which may occur almost immediately after it returns to its normal position.

To retard the movements of lever, 8, a liquid dash pot container, M, is connected to the end of lever, 8 by rod, l5. Container, 14, moves within the outer container, l3. A small port, it is provided in thebottom of container, M. A cleaner rod, ll, preferably is fixed to container, l3 and extends through port, [6, so that the movements of container, M will keep the small port from be coming choked.

A source of current, preferably a dry battery, l8 provides for energizing the coil, 3. A manually adjustable resistance, and switch 2'5, pro vides for so adjusting the how of current that the first oscillation of the wheel from its normal position may not rotate it more than through an angle ofabout-45 degrees,

A wire, is, connects one terminal of battery, l8, to the pivot of wheel, 5, from which the current fiows to the wheel, and thence to the arm, 1'. A wire, 20 connects the remaining terminal of battery, 18, to one terminal of the variable resistance, 21. A wire, 20' connects the remaining terminal of the resistance to one terminal of the primary winding of coil, 3. From the remaining primary terminal, a wire, 22, extends to the armature lever, 4, which, in turn, normally contacts the arm, 1', thus completing the circuit, and allowing current to flow from the battery through the primary coil winding. Secondary terminal 4' is connected by wire, 2' to fence wire, 2", and terminal, 4" by wire, 5 to ground plate, 5".

When put into operation, as by moving the variable resistance and switch to a closed position, the energizing of the coil core causes the armature lever to move sharply toward the coil, throwing wheel, 5, to rotate through an arc of about 45 degrees. The extent of this first oscillation of Wheel, 5, may be controlled as desired by placing the variable resistance at any desired point. As the wheel moves from its normal position the circuit becomes broken by the separation of the armature lever point 6' from the wheel point 6". This allows a sudden collapse of the magnetic field causing a high tension surge to be communicated to the secondary winding terminals, 4', 4". The balance spring, 6 then causes the wheel to immediately return to its normal position to close contacts 6' and '6", and the momentum of the returning wheel causes the armature spring lever, 4, to be deflected away from the coil. The closing of the circuit causes a second movement of the armature lever, this movement being increased in power over the first movement, because the deflected spring lever adds to the force, also this deflection of lever 4 causes a longer period of contact with a consequent nearer approach to saturation of the coil core, for, normally, the contact is of such short duration that the coil core is not at all fully saturated. These additions to the force moving the wheel cause each succeeding movement to be greater than the preceding one, so that after a few movements the wheel rotates sufiiciently for post, 7, to engage and pass the lever tip, 5 I, as has been described. The oscillations of the Wheel then cease until post i has moved past lever arms, 8 and H], as has been described. The movements of lever arms, 8 and It may be delayed as desired, within wide limits, by varying the size of the port, H6, in dash pot container, I4.

- As the angle through which the wheel rotates becomes greater, its return movement gains in force so that the =armature lever is deflected more as the arm, I engages it, as has been mentioned. The resulting greater period of contact, with its nearer approach to saturation of the coil core results in an increase in the strength of the high voltage surges from the secondary coil, as the angle of movement builds up. This is a great protection to stock, because the periods of interruption are preferably of much longer duration than the periods of operation. Therefore any stock that may contact a wire to which this unit is connected will likely do so during a period of inoperation, so that the first shock produced will be a weak, or comparatively low voltage shock, giving opportunity for the animal to escape before stronger shocks occur.

This method of graduating the shocks also provides automatic protection from sudden variations as to Wet or dry conditions of the ground, as shocks become more efiective under wet weather conditions.

In case it is desired to operate the unit continuously, in the usual way, this may be accomplished by so adjusting the variable resistance that the movements of the balance wheel never attain to more than about one half of a complete revolution. The shock impulses then become of uniform strength and the operation is continuous.

What I claim is:

1. In an electric fence shock producing system, a shock producing unit, said unit comprising an electro-magnet core, a primary winding of comparatively coarse wire on said core, also a secondary winding of finer wire on said core, suitable terminals for said windings, an inertia means pivoted to oscillate near said core, an armature lever fiexibly mounted near one end of said core, the free end of said lever being disposed to mechanically and electrically engage said inertia means, to mechanically energize said inertia means when said armature lever is drawn toward. said core, a spring disposed to move said inertia means in a direction opposite to said armature lever movement, and to cause said inertia means to normally contact said armature lever, a manually controllable electrical variable resistance, a source of electric current, said source of current being so connected that current normally flows through said variable resistance and through said primary winding, thence through said armature lever to said inertia means, and thence back to said source of current, a post fixed to said inertia means, a control lever having a cam assembly fixed thereto, and pivoted to move near said inertia means, to periodically interrupt the movements or said inertia means, said assembly comprising an arm fixed to said lever, a cam block fixed to said arm, and a spring tip fixed to said block in such a manner that when said post has moved to the desired position it engages one side of said spring to first deflect it in one direction, then as said post moves beyond and reverses its movement, it reengages said spring and cam block, on the opposite side, to retard the movement of said post and inertia means and to simultaneously cause said lever to be moved suificiently to eventually release said post, a second arm fixed on said lever near the opposite portion of said inertia means, said second arm bearing a cam block and a spring tip which are suitably formed and disposed to engage said post after it has moved from said first arm, to further retard the movement of said post and to provide that the movement of said lever may become reversed until said post is released, allowing said inertia means to return to its normal position, a mechanical yieldable resistance connected in operable relation with said lever to retard its movements, an insulated fence Wire, one of said secondary terminals being in electrical connection therewith, a ground rod member and an electrical conductor from said ground member to the remaining secondary terminal.

2. In an electric fence charging system, a shock producing unit, said unit comprising an electromagnet core, a primary winding on said core, a secondary winding of very fine wire on said core, suitable terminals for said windings, an inertia means pivoted to oscillate near said core, an armature lever flexibly mounted near one endoi said core, the free end oisaid lever being disposed to mechanically and electrically engage said inertia means to mechanically energize said inertia means when said armature lever is drawn toward said core, a spring disposed to move said inertia means in a direction opposite to said armature lever movement, and to cause said inertia means to normally contact said armature lever, a manually controllable variable electrical resistance, a source of electric current, said source being so connected that current normally flows through said resistance and through said primary winding, thence through said armature lever to said inertia means, and thence back to said source of current, a post fixed to said inertia means, a control lever pivoted to move near said inertia means, to periodically interrupt the movements of said inertia means, an arm and cam block fixed to said lever, a flat spring fixed to one end of said cam block in such a manner that when said post has moved to a desired position it engages one side of said spring to first deflect it in one direction, then as said post moves beyond the end of said spring and reverses movement it reengages said spring and cam block on the opposite side to retard the reverse movement of said post and inertia means and to simultaneously cause said lever to be moved sufliciently to eventually release said post, a mechanical yieldable resistance connected in operable relation with said lever to retard its movements, an insulated fence wire, one of said secondary terminals being in electrical connection therewith, a ground rod member and an electrical conductor from said member to the remaining secondary terminal.

3. In an electric fence charging unit, an electro-magnet core, a primary winding on said core, a secondary winding of finer wire on said core, suitable terminals for said windings, an inertia means pivoted to oscillate near said core, an armature lever flexibly mounted near one end of said core, the free end of said lever being disposed to mechanically and electrically engage said inertia means, to mechanically energize said inertia means when said armature lever is drawn toward said core, a spring disposed to move said inertia means in a direction opposite to said armature lever movement, and to cause said inertia means to normally contact said armature lever, a post flxed to said inertia means, a control lever and lever assembly pivoted to move near said inertia means to periodically interrupt its movements, said assembly comprising an arm fixed to said lever, a cam block fixed to said arm, a flat spring fixed to said cam block in such a manner that when said post has moved to a predetermined position said post engages one side of said spring to deflect it first in one direction then as said post moves past said spring and reverses its movement it reengages said spring and cam block on the opposite side to retard the reverse movement of said post and inertia means and to simultaneously cause said lever to be moved sufiiciently to eventually release said post, a mechanical yieldable resistance connected in operable relation with said lever to retard its movements, a manually adjustable electrical resistance, a source of electric current, said source being so connected that current normally flows through said resistance and through said primary winding, thence through said armature lever to said inertia means, and thence back to said source of current.

4. In an electric fence charging unit, an electro-magnet core, a primary winding on said core, a secondary winding on said core, suitable terminals for said windings, an inertia means pivoted to oscillate near said core, an armature lever flexibly mounted near one end of said core, the free end of said lever being disposed to mechanically and electrically engage an arm extended from said inertia means, to mechanically energize said inertia means when said armature lever is drawn toward said core, a spring disposed to move said inertia means in a direction opposite to said armature lever movement, and to cause said inertia means to normally contact said armature lever, a post fixed to said inertia means, a control lever and lever assembly pivoted to move near said inertia means to periodically interrupt its movements, said assembly comprising an arm fixed to said lever, a cam block fixed to said arm, a flat spring fixed to said cam block in such a manner that when said post has moved to a predetermined position, said post engages one side of said spring to deflect it, then as said post moves past said spring and reverses its movement, it reengages said spring and cam block on the opposite side, to retard the reverse movement of said post and inertia means, and to simultaneously cause said lever to be moved sufl'iciently to eventually release said post, a mechanical yieldable resistance connected in operable relation with said lever, to retard its movements, a source of electric current, said source being so connected that current normally flows through said primary winding, thence through said armature lever to said inertia means, and thence back to said source of current.

THADDEUS S. HARRIS. 

